MAP Sensor question

What should a map sensor on a 99GT read 1500-2000RPM mine is 7.7 - 8.0 Hg

What should a map sensor on a 99GT read 1500-2000RPM mine is 7.7 - 8.0 Hg

In Hg it sounds about right but I am not 100% sure. I have the readings for a Tech II and normally MAP and BARO reads out in kPa. On a Tech II, MAP pressure will increase as rpms increase as rpms are taken up to 3,000.

There is a high probability your MAP sensor is good. The vacuum reading at 20 in hg backs it up. All the MAP does is measure changes in intake manifold pressure, in essence vacuum.

The PCM controls and references MAP by sending a 5 volt reference signal to the MAP at the electrical connector. The MAP will then send a range of 2 to 4 volts signal back to the PCM. 2 volts at closed throttle (high vacuum) and 4 volts at open throttle (low vacuum). You could check the MAP sensor this way with a mulitimeter.

One indication of a bad MAP is high IAC counts. High IAC counts will produce a high idle so if your idle is normal you can rule this scenario out. MAP will also affect the EGR valve flow test. If MAP and vacuum is bad it will most likely trigger a P0401 DTC error code which is EGR related.

Hope the info helps and does not mix you up. Good luck!

I was doing some reading and it seems you take baro pressure - what the vac gauge says and that gives you your map number. so my baro was 28.XX - 20" of vac that would give my 8 that the scanner was seeing. Dang car:banghead:

yes i have a 1989 grand grand prix se pepsi special edition for sale only 500 hundreed were made.high miles runs good new exhaust new tires needs drives seat upholsterd.runs great.send offer to [email protected]